Method of making a mat

ABSTRACT

A method of making a mat with a textile surface and an elastomer backing is provided. The method includes mixing elastomer crumbs and a binder, depositing the crumb/binder mixture in a layer ( 22 ), placing a textile surface element ( 34 ) on the layer to form a mat assembly, and pressing the mat assembly in a press ( 9 ) while setting the binder. The elastomer crumbs are consolidated to form an elastomer backing ( 2 ) that includes voids between the elastomer crumbs, and the textile surface element is bonded to the elastomer backing to form the upper textile layer ( 1 ) of the mat.

TECHNICAL FIELD

The present invention relates to a method of making a mat having atextile surface and an elastomer backing.

In particular, but not exclusively, the invention relates to a method ofmaking a floor mat. The invention also relates to methods of makingother mats and mat-like products, including for example table mats andbar runners.

BACKGROUND TO THE INVENTION

Floor mats having a textile surface and a rubber backing are very wellknown and have been manufactured for many years. Typically, such matsinclude a tufted pile textile surface, for example of nylon, cotton,polypropylene or a mixture of such fibres, which is bonded to a rubberbacking sheet. Such mats are usually made by bonding the textile surfacelayer to a sheet of uncured rubber in a heated press. The heat from thepress vulcanises (cures) the rubber and at the same time bonds it to thetextile layer. A process for manufacturing such mats is described in EP0 367 441 A. Such mats have very good dust control characteristics, arehighly effective at removing dirt and moisture from the feet ofpedestrians, and have a good feel and appearance. The mats are alsowashable, extremely durable, highly flexible and lie flat on the floor.

Rubber backed floor mats with surfaces made of other textiles are alsoknown. These textiles may include knitted, woven, or non-woven fabrics(such as needle felts or spun-bonded fabrics), with or without a pile orraised nap, as well as flocked surfaces. The textile surface may bebonded under pressure to a rubber backing sheet, using a process similarto that described above. Other mats and mat-like products, such as tablemats and bar runners, have also been made in a similar fashion.

One disadvantage of the mats described above is that they tend to berather expensive, owing to the relatively high cost of the rubberbacking material. As a result, those mats have enjoyed only limitedcommercial success in certain market sectors, where a lower cost productis required. For example, in the commercial and retail or residentialmarket sectors, rubber backed dust control mats have achieved a marketpenetration of only about 5% of total mat sales, the remainder of thematting sold into this market sector being either unbacked or backedwith PVC or latex.

However, PVC and latex backed mats do have a number of disadvantages ascompared with conventional rubber backed mats. In particular, PVC backedmats have poor flexibility, especially at low temperatures, and afterbeing unrolled such mats often do not lie flat on the floor. They alsohave an inferior appearance and feel when compared with rubber backedmats, can become brittle with age, and can have poor resistance tomovement when placed on top of carpet. There are also growingenvironmental concerns associated with the manufacture and disposal ofPVC backed mats. These disadvantages have, however, been tolerated incertain market sectors, owing to the lower cost of the mats.

Recycled rubber has been used effectively at a low cost substitute forvirgin rubber in certain applications. Some examples of suchapplications are discussed below:

EP 0135595 describes a method for manufacturing a floor covering in theform of a web, which may be used as a sports surface. The web consistsof a lower textile base and an upper layer of disintegrated waste rubberand/or granules of new or scrap rubber that has been mixed with apre-polymer as a solvent-free single-component binder, spread on aconveyor belt, compressed and subsequently cured.

DE 4212757 describes a moulded component forming an elastic layer andcomprising a mixture of granulated recycled material and binders. Thecomponent has three compressed layers of uniform thickness bondedtogether at their interfaces. Upper and middle layers are formed by flatplates and the lower layer has hump-shaped feet separated by grooves.The individual layers are formed in different materials with differentparticle sizes. The component can be used as a covering, for example forfloors.

A mat with a compression moulded rubber crumb backing and having a flocksurface applied to the backing is available under the brand name “Royalmat”. The compression moulded backing is made by mixing rubber crumbwith a binder and then compressing a layer of the mixture in a mould ata high pressure while the binder bonds the crumbs together. The flockedtextile surface is subsequently applied to the backing using anadhesive.

Compression moulding produces a rubber crumb backing that has a highdensity and low deformability. This makes the mat heavy and inflexible,with the result that it does not conform well to the shape of the floorbeneath it. The mat does not therefore have the performancecharacteristics of a conventional rubber backed mat.

Rubber carpet underlay manufactured from lightly bonded crumb rubber isalso known. The underlay is however made without any significantpressure and as a result it is not sufficiently well bonded to make itdurable enough for use as a mat backing.

Notwithstanding the aforesaid applications, recycled rubber does nothave the same performance characteristics as virgin rubber. Inparticular, it has a lower tear resistance and a higher stiffness, owingto the presence of a binder material. As a result, recycled rubber hasnot generally been thought suitable for use as the backing material fora mat, since it has been thought to offer no significant advantages overPVC.

It is therefore desirable to provide a method of making a mat usingrecycled rubber, which produces a mat that overcomes the performanceshortcomings of PVC backed mats and compression moulded mats and avoidsthe relatively high cost associated with conventional rubber-backedmats.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided amethod of making a mat with a textile surface and an elastomer backing,the method including mixing elastomer crumbs and a binder, depositingthe crumb/binder mixture in a layer, placing a textile surface elementon the layer to form a mat assembly, and pressing the mat assembly whilesetting the binder, so that the elastomer crumbs are consolidated toform an elastomer backing that includes voids between the elastomercrumbs, and the textile surface element is bonded to the elastomerbacking.

Throughout this specification the term “crumb” has the normal meaning inthe rubber industry of any “broken down” rubber: thus, a crumb of rubbercan be any size in a range that includes powder, granules and chips. Theterm “powder” means crumb that will pass a 2 mm mesh or crumb with amaximum dimension of 2 mm as the context requires. “Granule” means crumbthat will pass a 6 mm mesh or crumb with a maximum dimension of 6 mm, asthe context requires. Granules may include some powder but are generallylarger than powder and have a weight average size that is near to themaximum of the size specification for the granule. “Chips” means crumbsthat are larger than granules.

It should be noted that any batch of rubber crumb normally contains aproportion of crumbs smaller than the nominal crumb size. Thus, forexample, we found that crumb made using a granulator with a 1.5 mmscreen (i.e. having holes of diameter 1.5 mm) had a distribution ofcrumb sizes, measured by using standard “Endecott” test sieves(ISO3310-1:2200, BE410-1:2000, ASTM E11:95), comprising by weight 72.82%in the range 1.0-2.0 mm, 17.45% of 0.71-1.0 mm, 6.90% of 0.5-0.71 mm,2.65% of 0.25-0.5 mm and 0.18% of 0-0.25 mm. Therefore, in the presentspecification, where we refer to 1.5 mm crumb, we mean crumb made usinga granulator with a 1.5 mm screen. Where we refer to “setting” thebinder, we mean either curing or heat-setting the binder, depending onthe nature of the binder.

We have found, surprisingly, that it is possible to make a mat havingsuperior performance characteristics with a backing made of elastomercrumb and a binder. In particular, we have found that by carefullycontrolling the pressure in the production process, we can produce a matwith voids between the elastomer crumbs in the backing, which meets orexceeds the performance of mats with a PVC backing layer and existingcompression moulded mats. The mat can be produced in a single process,using relatively inexpensive materials (for example, recycled rubberfrom old mats), and therefore provides a high performance but low costalternative to conventional rubber-backed mats, compression moulded matsand PVC mats.

The presence of voids between the crumbs increases the flexibility ofthe backing, thereby compensating for the stiffening effect of thebinder and providing a deformability that is comparable to that of aconventional rubber backing. The mat is more flexible than bothcompression moulded rubber backed mats and PVC backed mats, in thelatter case particularly at low temperatures. The tear strength of thebacking is however much greater than that of granulated rubber carpetunderlay, and is adequate for most mat backings, even in unsupportedborder regions of the mat. The backing is also extremely stable whenplaced on top of carpet, probably because the pile fibres of the carpetare gripped in the numerous small gaps between the crumbs of thebacking. It is also relatively light and it has good fire resistancecompared to a conventional rubber backed mat.

Advantageously, the mat assembly is pressed at a pressure of up to 16psig (110 kPa), preferably in the range 2-8 psig (14-55 kPa).

Advantageously, the mat assembly is pressed such that the thickness ofthe elastomer backing is in the range 60-100%, preferably 65-80%, of thethickness of the un-pressed crumb/binder layer.

Advantageously, the mat assembly is pressed at a temperature of 50° C.to 200° C., preferably 110° C. to 140° C., and most preferablyapproximately 125° C.

The mat assembly may be pressed in a plurality of stages including a lowtemperature stage and a higher temperature stage. If the binder isselected from the group comprising thermosetting and water curablepolymeric materials and mixtures thereof, the mat assembly is preferablypressed in a plurality of stages including at least one low temperaturestage followed by at least one higher temperature stage. Alternatively,if the binder is selected from the group comprising thermoplasticpolymeric materials, hot melt binders and mixtures thereof, the matassembly is preferably pressed in a plurality of stages including atleast one high temperature stage followed by at least one lowertemperature stage.

The mat assembly may be pressed in a press having an inflatablediaphragm. The press may be a heated press, which may include aplurality of zones, including a low temperature zone and a highertemperature zone. Advantageously, the mat assembly is transportedthrough the press in a plurality of steps, so that it is pressedsequentially in each of the plurality of zones. The mat assembly may betransported through the press on a conveyor, and the crumb/bindermixture may be deposited on the conveyor using a spreader device thatmoves at a constant speed relative to the conveyor. Advantageously, thespreader device includes a vibrating doctor blade.

A continuous textile element may be laid on the crumb/binder layer.Alternatively, separate textile elements may be laid consecutively onthe crumb/binder layer. The elastomer is preferably rubber, and morepreferably nitrile rubber. This backing material provides betterperformance than PVC at a cost that may be less than PVC and without theenvironmental concerns associated with PVC. Nitrile rubber is a termused to describe a compounded rubber mixture of which the main polymericcontent is an acrylonitrile butadiene copolymer. It may also containfillers such as carbon black, a curing system, plasticisers and otherancillary components.

Advantageously, the elastomer backing exhibits a deformability from atleast 14% as measured by the test herein defined. Preferably thedeformability is 14 to 50%, more preferably 14 to 25%.

Advantageously, the elastomer backing has a bulk density in the range 45to 70%, preferably 55 to 70%, of the elastomer from which the crumbs aremade.

Advantageously, the backing has a density of less than 1 g/cm³. Thebacking preferably has a density in the range 0.5 to 0.9 g/cm³, morepreferably 0.7 to 0.9 g/cm³.

Advantageously, the backing exhibits a tear resistance strength of atleast 0.8 N/mm². Preferably the tear resistance strength is about 1.5N/mm² or higher.

The mat backing preferably has a thickness of a least 1 mm. The crumbsize may be within the range of about 0.8 mm to about 6 mm, with crumbsizes less than about 5 mm diameter being generally preferred. Morespecifically, crumb sizes within the range of about 2 mm to about 4 mm,and preferably sizes of about 3 mm or less, have been found to beparticularly advantageous for use. The choice of crumb size to be used,and the relative percentage of powder used, if any, depends somewhatupon the desired performance characteristics of the mat and the desiredmanufacturing cost. Because use of small crumb (say, for example, powderless than about 1 mm) tends to require increased use of binder andthereby increased manufacturing cost, limiting use of crumb to smallgranules and large powder (e.g., crumb within the range of about 1 mm toabout 4 mm or, preferably, predominantly crumb within the range of about2 mm to about 3 mm) may be preferred if minimizing manufacturing cost isimportant.

The use of powdered crumb increases the strength of the resultingbacking, and generates a smoother appearance, but increases the cost ofproduction, both in the need for additional grinding and in the need forthe use of additional binder. Accordingly, the amount of powdered crumbcan be adjusted to suit the needs of the product; typically, includingpowder of at least 10% by weight has been found useful. The elastomercrumb is preferably at least partially comprised of crumbed vulcanisedrubber. The rubber is preferably nitrile rubber. The elastomer crumb mayinclude a combination of crumb sizes in addition to the powderedelastomer crumb.

The binder may be comprised of any of several different materials. Forexample, the binder may be a polyurethane MDI binder. Preferably it isselected from the group consisting of 4,4-methylene di-p-phenyleneisocyanate (MDI) polyurethane one- and two-component adhesives.Advantageously the binder is a solvent-free, one component (moisturecuring) polyurethane adhesive. Such binder may typically be present at alevel of from 4 to 12%. Alternatively the binder may be a hot meltbinder and is desirably present at a level of from 3 to 10%. Whenpowdered elastomer crumb is included in the crumb/binder mixture and thebinder is a one component polyurethane adhesive, the binder levelpreferably lies in the range 9 to 20%, as may be determined byexperimentation. Exceptionally, binder levels of up to 25% may beemployed.

The crumb/binder mixture may include powdered or liquid additivesselected from the group consisting of: anti-microbial additives,anti-flammability additives, pigments such as iron oxide, andanti-static additives such as carbon fibres. This provides addedfunctionality to the mat.

Advantageously, a crumb rubber border extending beyond the periphery ofthe textile surface is provided on at least two opposite edges of themat, by spreading the crumb/binder mixture over a larger area than thetextile element or elements. The crumb rubber border may be providedaround the entire periphery of the mat.

Advantageously, the textile surface comprises a tufted pile textile,including tufts of yarn tufted into a tufting substrate. Alternatively,the textile surface comprises a knitted, woven or non-woven textile, ora flock surface.

An edging strip may be bonded to the elastomer backing adjacent at leastone edge thereof. Advantageously, the textile surface element partiallyoverlaps and is bonded to the edging strip.

The mat may be a floor mat, a table mat, a bar runner or any other mator mat-like product.

Often, commercial or retail floor mats are backed with PVC. Theadvantage of mats made according to the present invention and backedwith elastomer crumb is that they are similar in cost of production toPVC mats and have superior appearance and feel to PVC mats. Furthermore,they have much better low temperature flexibility than PVC, which meansthat the elastomer crumb backed mat lies better on the floor than a PVCbacked mat. The mat is also less liable to become brittle with age thana PVC backed mat. In tests, we found that crumb rubber backed matsremained sufficiently flexible to unroll and lie flat immediately afterbeing removed from storage at minus 16° C. Mats made according to theinvention also unroll more easily than PVC mats at higher temperaturesand tend to give off less of a distinctive odour of rubber thanconventional vulcanised rubber mats. The ability to roll up is veryimportant for commercial mats as they are often over 6 m long and can beas long as 25 m. It is also important for retail mats as they arefrequently sold in rolled up form to enable the larger sizes to becarried home. The lie flatness or amount of rippling of the mat edgesafter both mats had been rolled up was visibly superior in the mat madeaccording to the invention.

The invention will now be further described by way of example only andwith reference to the drawings, which are briefly described as follows:

FIG. 1 is a cross-sectional side elevation of a mat;

FIG. 2 is a top plan view of the mat;

FIG. 3 is an enlarged partial bottom view of the mat;

FIG. 4 is a side elevation of a machine for manufacturing the mat;

FIGS. 5A to 5D are photographs showing in cross-section the structure ofvarious rubber crumb backing layers;

FIG. 6 is an exploded side view of a laid-up mat assembly, prior topressing, according to a second embodiment of the invention, and

FIG. 7 is an enlarged partial cross-sectional side elevation of a matmade according to the second embodiment of the invention.

With reference to FIGS. 1 and 2, a mat is shown with a textile surface 1bonded to a nitrile rubber crumb backing 2. In this case, the textilesurface is shown as a tufted pile textile. It should be understoodhowever that other textiles may also be used including, for example,knitted, woven and non-woven fabrics, as well as flocked surfaces.

The textile surface 1 includes a tufted pile, which is tufted onto asubstrate (or primary backing), for example of woven or non-wovenpolyester or polypropylene. The tufted pile can be cut, looped or both,and typically consists of cut pile. Suitable textile materials includepolypropylene, nylon, cotton, blends thereof and any other fibres oryarns that can be tufted into a tufting substrate to form a pilesurface. The yarn may be solution dyed or the mats may be printed duringor after manufacture.

The textile surface 1 is slightly smaller than the backing, leaving arubber crumb border 3 that extends around the periphery of the mat.Alternatively, the border strips may be omitted entirely or two borderstrips may be provided on opposite sides of the mat, with no borders atthe ends of the mat. This latter construction is preferred for rolls ormatting. The width of the mat and the other dimensions may be any ofthose conventionally used for commercial or retail mats or any othersuitable dimensions. For mats with a low backing thickness, it isadvantageous for the textile surface to cover the whole upper surface ofthe backing. For aesthetic reasons, such mats are often provided withwhat is termed an “optical border”, which is a dark printed area aroundthe periphery of the mat.

FIG. 3 shows the rubber crumb backing 2 in more detail. It generallycomprises a series of rubber crumbs 6 bonded together with a binder (notshown), which bonds each crumb to the adjacent crumbs. The binder alsobonds the backing 2 to the textile surface 1. A plurality of voids 7exist between the rubber crumbs, some of which may be partially or fullyfilled with the binder. Owing to the presence of the voids, the bulkdensity of the backing layer is less than the density of the solidrubber material of which the crumbs are composed, and is typically about45%-70% of the solid rubber density.

Generally, any batch of granules will include a distribution of granulesizes, the average granule size being significantly less than themaximum that will pass through the mesh. For example, we have found whenusing a 4 mm mesh that the majority of the granules lie in the range 1to 3 mm (i.e. they will pass through a 3 mm mesh but not a 1 mm mesh).Further, it should be noted that the granules tend to be irregular inshape and often have a thickness that is considerably less than thenominal granule size. Thus, with the compaction that occurs during thepressing process, we have found that a backing layer can be made usinggranules having a nominal size larger than the thickness of the backinglayer.

The crumb is preferably nitrile rubber, and is preferably rubber fromrecycled industrial mats. The rental industrial segment is an idealsource of raw material for the crumb because it ensures that low bleed,low staining nitrile rubber crumb is used as the starting point for theproduction of the mats. The crumb may include some flock from thetextile surface of the original mat, perhaps in bonding relationship tothe crumb. The flock content should preferably be as low as possible,most preferably less than 10% by weight.

The crumb size may range from about 0.01 to 8 mm. Generally, the size isselected to be as large as possible for the use and properties required.However, crumb larger than granules (i.e. larger than about 6 mm) may beregarded as excessively granular, and crumb that is smaller than about0.8 mm may be regarded as excessively costly (both in terms of supplyand increased binder requirements). Generally, it has been found thatcrumb within the range of about 2 mm to about 4 mm is preferred.Specifically, crumb that passes a 4 mm aperture screen (i.e. crumbpredominantly of about 3 mm or less) has been found to be particularlyuseful for floor mats. In accordance with the teachings herein, powder(i.e. crumb less than 2 mm in size) may be used as desired. Crumb sizecan be chosen to give different amounts of resilience in the mat. Wehave found that larger crumbs provide greater resilience.

Crumb may be mixed with powder of the same material or a differentmaterial to provide a greater tear resistance. We have found that thepowder increases the tensile strength for a given binder level. The useof other additives in powdered or liquid form may provide the same ordifferent advantages. Suitable additives include, but are not limitedto, anti-microbial materials, anti-flammability additives, odorants,colorants or pigments such as iron oxide powder, anti-static additivessuch as carbon fibres, fillers and other generally known additives.

The binder may be either a heat setting or thermoplastic type. Dependingon the process utilized to manufacture the backing, the binder can be inliquid or powder form. Preferably, the binder is selected from one ofthe following types: polyurethane reactive hotmelts, copolyester orcopolyamide reactive and thermoplastic hotmelts, and 4,4-methylenedi-p-phenylene isocyanate (MDI) polyurethane one- and two-componentadhesives.

It is important that the binder has good adhesive properties to ensurethat the crumb is well bound, and that sufficient free binder isprovided to be capable of forming a physical or chemical bond to thetextile surface. The binder should also exhibit sufficient cohesivestrength to give the backing sufficient strength. When a tufted piletextile is used, the binder should be one that cures or sets at asufficiently low temperature and pressure that pile crush issubstantially avoided.

The binder may contain any of the known cross linkers or curingaccelerators to suit the process and the desired properties of the matbeing manufactured and the rubber being used.

The binder performs the dual function of holding together the crumb toform a backing and bonding the backing to the textile surface of themat. To perform both functions adequately we have found that binderlevels should be in the range 2 to 12% by weight of the crumbs whenchips or granules are used. Use of less than 2% binder gives a very poortensile strength in the backing. Use of greater than 12% gives a stiffbacking and causes a skin to form. When rubber crumb powder is added tothe backing, the amount of binder needed for optimal properties isgreater due to the higher surface area of the rubber crumb powder on aweight for weight basis. For powders, especially finer rubber crumbpowders of size less than 0.5 mm, the quantity of binder should lie inthe range 9 to 20%, depending upon the size and quantity of the powderadded. Because the powder addition increases the tensile strength,inclusion of a little powder can improve the strength of the backingwithout increasing the binder content excessively.

Generally, there is an inverse relationship between the binder contentand size of the rubber crumb, and between the binder content andpressure applied to the rubber crumb while forming the backing layer.Therefore, as the crumb size and the pressure increase, the bindercontent decreases. The binder content also depends on other factors,such as the type of binder, the rubber material used and the type offabric, and can be determined by routine experimentation.

For example, the binder may be a liquid polyurethane MDI binder, inwhich case it is preferably present at a level of from 4 to 12% if thebacking consists primarily of chips or granules. The binder may containfurther additives that are in liquid form and are compatible with thebinder, such as colorants, plasticisers and perfumes. The binder mayalso contain other additives, such as those listed as crumb additives,provided that they are suitable for addition in a liquid medium.

The binder may alternatively be a thermoplastic or thermosetting hotmelt powder, in which case it is preferably present at a level from 3 to10% if the backing consists primarily of chips or granules. A powderedbinder may also contain other additives such as those listed as crumbadditives, provided that they are suitable for addition in a powdermedium.

The preferred ranges for binder content may thus be summarized asfollows:

Backing of chips/granules: binder content in range 2 to 12%, preferably4 to 12% with an MDI binder or 3 to 10% with a hot melt binder.

Backing with ≧10% powder: binder content in range 9 to 20%, preferably14% or more.

Exceptionally, a binder content of up to 25% may be employed, eventhough this may lead to the formation of a skin.

Examples of mat products according to the invention are given in Table1.

TABLE 1 Example Products Floor mat—tufted Floor mat—tufted nylon onrubber Bar runner— Poster mat— polypropylene granule backing knittedpolyester woven polyester fabric on rubber with printed optical fabricon rubber on rubber granule Property powder backing borders powderbacking backing Textile Type Polypropylene Nylon 6 Polyester PolyesterWeight  500 gm⁻²  600 gm⁻²  237 gm⁻²  200 gm^(–2) Method Tufted TuftedKnitted Woven Tufting substrate  80 gm⁻² Polyback  140 gm⁻² Colback n/an/a Backing Material   0.8 mm powder   3 mm granule   0.5 mm powder   4mm granule (screen size) Thickness   1.5 mm   4.0 mm   1.0 mm   1.5 mmWeight 2000 gm⁻² 3000 gm⁻² 1333 gm⁻² 2000 gm⁻² Total Weight 2580 gm⁻²3740 gm⁻² 1570 gm⁻² 2200 gm⁻² Borders  15 mm None None None gm^(–2) isgrams per square meter

A process for making the mat of FIGS. 1-3 will now be described withreference to FIG. 4, which is a sectional side view of a machine formanufacturing mats, showing a mat during manufacture. The machineincludes a conventional heated press 9 that comprises a heated metalplaten 10, above which there is an inflatable diaphragm 12, mounted on aframe 14. The platen 10 is divided into a first section 10 a and asecond section 10 b, which can be heated to different controlledtemperatures. The inflatable diaphragm 12 is arranged to be inflated toa controlled pressure and subsequently evacuated under automaticcontrol.

A motor driven conveyor belt 16 extends around and beyond the heatedplaten 10, and includes an input portion 16 a on one side of the press 9on which mats can be laid up, and an output portion 16 b on the oppositeside of the press, on which mats are transferred out of the press 9. Thebelt 16 is made, for example, of PTFE-coated woven glass fabric, toprevent the mats from sticking to it. In use, the conveyor belt 16advances stepwise in the direction of arrow A, so that mats aretransferred through the press in a number of discrete steps.

A release belt 18 is mounted on rollers 20 and arranged for rotationaround the diaphragm 12 and the frame 14, as the conveyor belt 16advances. The release belt 18 is made, for example, of PTFE-coated wovenglass fabric, to prevent the rubber backing sheet of the mat fromsticking to it or the diaphragm 12.

A crumb mixing and spreading apparatus 20 is mounted above the inputside 16 a of the conveyor belt, to deposit a layer 22 of a rubber crumband binder mixture on the belt. The apparatus 20 includes a hopper 24for rubber crumb, a feed tube 26 containing a feed/mixing screw (notshown) and a spreader 28 for spreading a layer of the rubbercrumb/binder mixture on the belt 16. The feed tube 26 includes inlets 30a,30 b for a liquid binder and an activator (water plus a catalyst),which are fed into the feed tube 26 at a controlled rate using meteredpumps (not shown). The binder and activator are mixed with the rubbercrumb in the feed tube 26 and the mixture is deposited onto the belt 16through the spreader 28.

The spreader 28 is arranged to deposit a layer of the crumb/bindermixture having a substantially uniform thickness. To achieve this, itmay consist of a distributor that distributes the mixture evenly acrossthe width of the belt 16, or alternatively it can be arranged forreciprocating movement across the width of the belt (in a directionperpendicular to the plane of the drawing).

To ensure that the crumb/binder layer 22 has a uniform thickness, adoctor blade 32 is mounted a fixed distance above the belt 16, betweenthe spreading apparatus 20 and the press 9. The doctor blade 32 ispreferably arranged to vibrate from side to side (in a directionperpendicular to the plane of the drawing), and/or up and down(vertically, in the plane of the drawing), to prevent the crumb materialfrom catching and building up under the blade.

The crumb spreading apparatus 20 and the doctor blade 32 are mounted ona motor driven carriage (not shown) for backwards and forwards movement(to the left and right in the plane of the drawing). When the diaphragmis inflated, belt 16 is stationary, the carriage moves slowly backwards(to the left) in the direction of arrow B, typically at a speed of about1 cm/sec, to deposit a layer of the crumb/binder mixture on the belt 16.When the diaphragm is deflated the belt advances, at which time thecarriage also moves forwards but at a slightly slower speed, so that itmaintains a constant speed relative to the belt. Thus, for example, ifthe belt advances at 100 cm/sec, the carriage will move forwards at 99cm/sec, so that its speed relative to the belt is always 1 cm/sec. Inthis way, a uniform layer 22 of the crumb/binder mixture can bedeposited continuously on the belt 16.

Fabric 34 for the textile layer of the mat is held on a reel 36 locatedbetween the doctor blade 32 and the press 9. The fabric 34 is laid onthe crumb/binder layer 22 as the belt 16 advances, creating a compositemat assembly that is drawn into the press 9.

Optionally, a take-up reel (not shown) may be provided above the outputportion 16 b of the belt, for removing the completed mat product fromthe machine. Alternatively, the finished mat can be cut up intoindividual mat portions, which can then be removed and stacked. Themachine may include a cutter for cutting the mat into individual matportions and/or for trimming the longitudinal (side) edges of the mat.

In operation, rubber crumb 38 is fed into the hopper 24 andbinder/activator supplies are connected to the inlets 30 a,30 b of thefeed tube 26. The press 9 is preheated to the required temperatures: forexample the first portion 10 a of the platen may be heated to atemperature of about 60° C., while the second portion 10 b is heated toa temperature of about 125° C.

The feed/mixing screw and the metering pumps are activated and rubbercrumb is fed through the feed tube 26 and mixed with the requiredquantity of binder/activator. This mixture is deposited onto the belt 16while at the same time the carriage carrying the spreading apparatus 20and the doctor blade 32 is driven backwards, to spread an even layer ofthe mixture on the belt.

When a layer of sufficient size has been deposited, the conveyor beltmotor is activated, driving the belt 16 forwards in the direction of thearrow A. As the belt 16 moves, the fabric 34 is laid on the crumb/binderlayer 22 and the crumb/fabric composite is introduced partially into thepress, so that it lies between the diaphragm 12 and the first part 10 aof the platen. The belt then stops and the diaphragm 12 is inflated, forexample to a pressure of about 4 psi (28 kPa), to press the fabric 34into the crumb/binder layer 22 and at the same time compress thecrumb/binder layer. However, as the first part 10 a of the platen is ata relatively low temperature, the binder is not fully cured at thisstage. This helps to prevent the formation of permanent boundaries orsteps between adjacent sections of the finished mat. In the meantime,the spreading apparatus 20 continues to deposit a layer 22 of thecrumb/binder mixture on the input part 16 a of the belt.

After a predetermined time (for example about 2 minutes), the diaphragm12 is deflated and the belt 16 is advanced a further step, carryinganother section of the mat assembly into the first part of the presswhile moving the section that was in the first part further into thepress, so that it lies between the diaphragm 12 and the second part 10 bof the platen, which is at a higher temperature. The diaphragm is theninflated again and the section of the mat assembly that is in the firstpart of the press is subjected a low temperature pressing as describedabove, while the section that is now in the second part of the press issubjected a high temperature pressing, which completes the setting ofthe binder. The time during which the diaphragm is deflated is kept asshort as possible (for example about 5 seconds), so that the pressureapplied by the press is released only for the minimum amount of time.

The pressing process is repeated continuously, so that the completed matproduct 40 emerges in stages from the press on the output portion 16 bof the conveyor belt, and is either wound onto a reel or is cut intoindividual mats and stacked, as described above.

Various modifications of the process described above are of coursepossible. For example, instead of using a continuous length of fabric toform the textile layer, individual fabric portions can be laid on thecrumb/binder layer to create separate mats. These fabric portions can belaid either manually or automatically, using a feeder device. By leavinggaps between the fabric portions, rubber borders can be provided at theends of the mats.

The spreading apparatus may include means for controlling thetemperature of the crumb/binder mixture in the feed tube 26, to preventthe binder from setting too rapidly. For example, the feed tube may beequipped with a jacket for cooling water. Alternatively, the rate atwhich the binder cures can be controlled by regulating the amount ofactivator added to the binder.

Instead of using a liquid binder, a thermoplastic or thermosetting hotmelt powder binder can be used, in which case it may be mixed in withthe rubber crumb in the hopper 24. The inlets 30 a,30 b on the feed tube26 are not then required. If a thermosetting hot melt powder binder isused, the first portion 10 a of the platen may be set to a highertemperature than the second part 10 b to melt the binder rapidly, andthe second part 10 b may be set at a lower temperature to maintain thecompression of the crumb/binder layer 22 while the binder cools andcures.

Although it is generally preferable that the press has the diaphragmabove the platen, an inverted press arrangement with the platen abovethe diaphragm can also be used.

We have found that by using the process described above, we can controlthe flexibility and strength of the backing by adjusting the pressureapplied to the backing in the press. By increasing the pressure thetensile strength of the backing can be increased, and by reducing thepressure the flexibility of the backing can be increased. The desiredperformance characteristics of the backing can thus be achieved bycareful control of the backing pressure.

Also, when tufted pile textiles are used, the problem of pile crush canbe substantially avoided. This is because the press operates at a muchlower pressure (typically, 4 psig/28 kPa) and temperature (about 125°C.) than is usual in a conventional mat presses, which typically operateat a pressure of 20 to 40 psig (140 to 280 kPa) or higher and at atemperature above 160° C. It may be possible to operate the press ateven lower temperature (for example down to about 50° C.) by the use ofsuitable binders. The lower pressure and temperature are possiblebecause the rubber crumb is already vulcanised and the heat and pressureonly have to be sufficient to activate the binder and press the granulestogether so that they bond to one another and to the fabric layer. In aconventional mat making process, a much higher pressure and temperatureis required to soften and cure the vulcanised rubber backing, and topress the fabric layer into the backing.

The mats provide a higher level of comfort and are less dense thancompression moulded mats, which have high-density backings. The mat issuited to the retail and commercial segments.

EXAMPLE

A batch of 0.8 to 3 mm rubber crumb was made up by granulatingvulcanised nitrile rubber in a granulator with a 3 mm screen and thenpassing the granules over a 0.8 mm screen to remove fines smaller than0.8 mm. The granules were then mixed with 8% MDI binder. The mixture wasdivided up and sample rubber mat backings were made by spreading thecrumb mixture evenly with a thickness of 8 mm and then pressing themixture using an air bag press at various pressures to produce a seriesof samples. The pressure ranged from no pressure in the air bag throughto 45 psig (310 kPa). All the rubber backing samples so formed were setor pressed at 125° C. for 10 minutes. A 25 mm square section was thencut from each sample and its thickness and weight were measured. Fromthis, the density of the sample and the bulk density of the rubber crumblayer were determined, the bulk density being expressed as a percentageof the density of the material from which the crumb was made. The dataare given in Table 2.

TABLE 2 Density Test Data Bulk Thick- Thick- Den- den- Pressure nessness Weight Volume sity sity Sample psig (kPa) mm % g cm³ g/cm³ % A 0(0)  8.1 100 2.8 5.06 0.55 45 B 2 (14) 6.2 78 2.8 3.87 0.72 59 C 4 (28)5.4 68 2.6 3.37 0.77 63 D 8 (55) 5.4 68 2.9 3.37 0.86 70 E 16 (110) 5.063 3.2 3.12 1.02 84 F 32 (220) 4.3 54 2.8 2.68 1.04 85 G 45 (310) 3.9 492.7 2.43 1.11 91 Royal 7.3 5.0 4.56 1.10 90 Rubber 1.22 100

The sample referred to as “Royal” is the backing layer of the prior art“Royal” mat referred to previously, which is formed by compressionmoulding rubber crumb in a fixed platen press to form a very densebacking. The sample referred to as “Rubber” is a solid vulcanised rubberbacking of a conventional floor mat.

It can be seen from Table 2 that the density increases as the pressureapplied increases. The maximum density achieved was 1.11 g/cm³,equivalent to a bulk density that is 91% of the density of the solidrubber backing. Theoretically, if the backing sample were 100%compressed to remove all voids the density would be about 1.22 g/cm³ tomatch that of the solid rubber backing of the conventional vulcanisedmat referred to as “Rubber”. From the table, it can be seen that thedensity of the compression moulded product (the “Royal” mat) is aboutthe same as the density we obtained using a 45 psi (310 kPa) pressure.

Table 2 also gives a general view of the backing thickness reductionfrom around 8 mm before to around 4-6 mm after pressing, representing areduction of up to 50% of its original thickness.

The samples were then tested to determine their deformability. This testwas done with a thickness gauge with a 10 mm diameter foot. Weight wasapplied to the measuring plunger of the thickness gauge. First the newbacking thickness was measured with 60 g weight and then the thicknesswas re-measured with a 800 g weight. The deformability is the percentagefall in the thickness at 60 g loading when the loading pressure wasincreased to 800 g. The results are shown in Table 3.

TABLE 3 Deformability Test Data Sample ID Pressure 60 g 800 gDeformability % A 0 7.65 4.0 47.7 B 2 5.70 4.3 24.6 C 4 5.10 4.2 17.6 D8 5.30 4.55 14.2 E 16 4.80 4.3 10.4 F 32 4.15 3.75 9.6 G 45 3.70 3.5 5.4Royal 7.45 7.05 5.4 Rubber 6.10 5.6 8.2

From Table 2 it can be seen that there is a correlation betweenformation pressure and density, and from Table 3 it can be seen thatthere is a correlation between pressure (density) and deformability.This correlation may be expressed as follows: the higher the formationpressure, the higher the density, and the higher the density, the lowerthe deformability.

In Tables 2, 3 and 4, the sample referred to as “Rubber” is acommercially available vulcanised rubber backed industrial mat. Thevulcanised rubber is softer and therefore more deformable than the highpressure crumb backings because of the presence of binder in the latter.The binder material is relatively hard, compared with vulcanised rubber,and this reduces the flexibility of the backing.

In the mat made by compression moulding (the “Royal” mat), the bulkdensity of the mat backing was about 90% of the density of the materialfrom which the crumb was made and is usually in the range of 80-95%. Thebacking is harder than the material from which the crumb was madebecause of the presence of the binder.

On the other hand, using the process according to the invention, thebulk density of the backing can be varied to lie within 45-90% of thedensity of the material from which the crumb was made. Preferably, thebulk density of the backing is made to lie within 45-70%, and morepreferably within 55-70%, of the density of the crumb material. Thisprovides a backing with a deformability of about 14-50%, more preferably14-25%, which is better than that of a compression moulded mat andcomparable to that of a conventional rubber backed mat. The inventionalso offers the advantage of a lighter weight mat that is more easilywashed and dried and easier to carry and transport, whilst still being arubber backed mat. This also has the advantage that the product densitycan be varied by a minor process change to enable productionflexibility. Additives could also be included in the crumb and bindermix to further control or change the density if required.

The effect of different formation pressures on the structure of thebacking layer is shown photographically in FIGS. 5A to 5D. FIG. 5A showsa cross-section at a magnification of about 10× through a backing layermade up from 1.5 mm rubber granules together with 8% MDI binder and 5%yellow oxide (which was added to binder to improve its visibility), andpressed at a pressure of 2 psi (14 kPa). Some of the granules werecoloured blue and others were coloured black, to allow the boundariesbetween the granules to be seen more easily (the blue granules appear alighter shade of grey). The individual granules can be easily identifiedand are substantially undeformed, having straight edges and sharpcorners. The granules are packed together as a loose conglomerationgiving the backing a sponge-like appearance. Many voids can be seenbetween the granules, those voids being generally only partially filledwith binder.

FIG. 5B shows a similar backing, produced at a pressure of 10 psi (69kPa). The backing has a tighter, more compact structure and some slightdeformation of the granules can be seen. This increases the area ofcontact between adjacent granules and increases the tear strength of thebacking. Nevertheless, many voids are still visible between thegranules, which are only partially filled with binder.

FIG. 5C shows a backing made using the same mixture of granules andbinder, but using a compression moulding process in a 20 tonne press. Inthis case, severe deformation of the granules has taken place and theboundaries between adjacent granules are almost unidentifiable, exceptwhere the granules have different colours. The backing layer is denseand virtually solid, with hardly any voids between the granules.

FIG. 5D shows a cross-section through a conventional compression mouldedmat (the prior art “Royal” mat). As with the backing layer shown in FIG.5C, the boundaries between adjacent granules are almost unidentifiableand the backing layer is dense and solid, with hardly any voids (exceptwhere the backing layer has fractured).

Tear Strength Test

To test the strength of the granulated rubber backing, a batch ofsamples was made up using different formation pressures, ranging from nopressure in the air bag through to 8 psig (55 kPa).

All the rubber backing samples so formed were set or pressed at 125° C.for 10 minutes. Six test pieces were then cut from each sample and thetear strength of each test piece was measured, with three measurementsbeing made in each of two orthogonal directions. The results are shownin Table 4.

TABLE 4 Tear Strength Test Data Tear Strength— Tear Strength— Direction1 Direction 2 Average Formation N/mm² N/mm² tear Pressure Test Test TestTest Test Test strength psi (kPa) 1 2 3 4 5 6 N/mm² 0 (0)  0.09 0.110.06 0.08 0.06 0.08 0.08 2 (14) 0.89 0.88 0.95 0.82 0.98 0.81 0.89 4(28) 1.59 1.56 1.51 1.48 1.45 1.48 1.51 8 (55) 1.41 1.55 1.57 1.52 1.551.48 1.51

Table 4 shows that there is a correlation between formation pressure andtear strength, the strength increasing rapidly up to a formationpressure of about 4 psi (28 kPa), but with no significant additionalincrease in strength at higher formation pressures. We have found that atear strength of about 0.8N/mm² or higher is quite adequate for many matapplications, even though this is considerably less than the tearstrength of a conventional solid rubber mat backing.

Pile Crush Test

For this test, we made a number of mat samples, each including a tuftedpile surface and a rubber crumb backing made using the same pressingtemperature, time and pressure values as set out in Table 2. The extentof pile crush and the commercial acceptable of the different mat sampleswere then assessed subjectively. We found that for pressures of about 8psig (55 kPa) and lower, pile crush was relatively minor and the productwas commercially acceptable. However, at pressures above about 8 psig(55 kPa), significant pile crush occurred and the product was consideredcommercially unacceptable without subsequently being laundered orprocessed in some other way to raise the pile. The preferred tufted pilemats are therefore those manufactured at a pressure of about 8 psig (55kPa) or less, which have backings with a bulk density in the range45-70% of the density of the solid rubber material from which the rubbercrumb is derived. The best mats were those manufactured at pressures of2-8 psig (14-55 kPa), which have a bulk density in the range of about55-70%.

Low Temperature Recovery Test.

For this test a 300 mm×200 mm sample of each product to be tested wasconditioned at a room temperature of 22° C. for 2 hours and then rolledlengthwise around a 40 mm diameter tube and secured with a cable tie.The samples were then placed in a freezer and kept at a temperature of−16° C. for 24 hours. The samples were removed from the freezer, thecable tie was cut and the samples were then left at 22° C. for 10minutes to relax on a flat, wood surface. Measurements were then made ofthe height, if any, of the ends of the mat samples above the flatsurface due to the curl of the sample. Repeat measurements were made at20 minutes and 60 minutes following removal from the freezer.

Table 5 shows the results of the above test when comparing: aconventionally backed nitrile rubber mat (A), a commercially availablemat backed with PVC (B), a prior art rubber crumb backed mat formed bycompression moulding in a fixed platen press to form a very densebacking (the “Royal” mat), and a mat according to the invention backedwith granulated nitrile rubber crumb (D).

TABLE 5 Prior art mats Inventive mat A: Regular rubber B: PVC backed C:Compression D: Rubber crumb Time backed mat mat moulded mat backed mat+10 minutes Flat (0 mm) 37 mm 50 mm 10 mm +20 minutes Flat (0 mm)  7 mm 6 mm Flat (0 mm) +60 minutes Flat (0 mm)  2 mm  2 mm Flat (0 mm)

The mat according to the invention outperforms both the PVC backed matand the compression moulded rubber crumb mat and it is not significantlydifferent in performance from a high specification conventional rubberbacked mat.

Sand Retention Test.

For this test two equal size samples of a mat (0.05781 m²) were cut out.Each sample was weighed. They were then fixed to the inside of atetrapod chamber. A tetrapod is a known piece of testing equipment usedto measure wear of carpeting and the like. 1000 g of dry sand with aparticle size distribution as shown in Table 6 was added along with fivegolf balls to provide agitation.

TABLE 6 Particle size mm Weight % 0.00–0.25 7.0 0.25-0.50 71.0 0.50-0.7115.7 0.71-1.00 3.5 1.00-2.00 1.7 2.00-2.80 0.16 2.80-4.00 0.02 4.00-6.700 6.70 and above 0

The chamber was then sealed to prevent either the golf balls or the sandleaking out during the test and it was set revolving for 1000revolutions. On completion of the test, each sample was removed and theweight increase of the sample recorded. The amount of sand retained ineach sample was then calculated and expressed as the amount of dry sandretained in g/m².

Two mats with identical tufted pile construction were subjected to thistest. The first mat was a tufted nylon cut pile conventional rubberbacked mat, which had been fabricated in an air bag press at 165° C. and30 psi (207 kPa). The mat was not washed prior to the test. The secondmat was a tufted nylon cut pile mat with a rubber crumb backing, whichhad also been fabricated in an air bag press but at a lower temperatureand pressure. The sand retention results were as follows:

Sample of prior art conventional rubber backed mat A: weightincrease=723 g/m²

Sample of inventive crumb rubber backed mat B: weight increase=2655 g/m²

Production of a conventional rubber backed mat significantly flattensthe pile on the mat. The lower temperature and pressure possible whenusing the same type of press (with a pressurised air bag and a heatedplaten) to produce a rubber crumb-backed, textile pile-faced mataccording to the invention results in a mat that does not suffersignificantly from pile crush. This gives a mat having, immediatelyafter manufacture, good dust control properties without being laundered.This good dust control performance is exemplified by a sand retentionvalue in excess of 2000 g/m² for the typical nylon tufted pile used inthis test. The sand retention performance for a mat according to theinvention is far superior to the sand retention performance of theconventional rubber-backed tufted nylon cut pile mat, prior to washing.The uncrushed pile also exhibits better “feel” by way of a moreluxurious texture.

The mats made according to the invention exhibit superior fireresistance to those made from conventional nitrile rubber backing of thesame thickness. When tested according to BS4790, mats made from powdernitrile rubber crumb and granule nitrile rubber crumb showedsignificantly higher resistance to ignition when compared to a mat madefrom conventional nitrile rubber backing. This is recorded in Table 7.

TABLE 7 Regular mat with solid Mat with crumb rubber backing granulebacking Time to extinguish (s) 170 50 Radius of effects top (mm) 50 25Radius of effects lower (mm) 50 25

This can be further improved by the addition of more binder and/oranti-flammability additives to the backing and is especially useful whenused in conjunction with a low flammability textile surface. Such a lowflammability textile surface may, for example, be one that ispredominantly a woollen construction.

When compared with PVC backed mats, the mats made according to theinvention that have 4 mm or larger crumb rubber in the backing havebetter resistance to movement on carpets. On average, these mats displaysignificantly improved resistance to movement on carpets compared withPVC backed mats.

A modified mat and a method of manufacturing the modified mat will nowbe described with reference to FIGS. 6 and 7. FIG. 6 is an exploded sideview of a laid-up mat assembly, prior to pressing, which includes abacking layer 22 comprising a mixture of rubber crumb and a binder, anda layer of fabric 34 that will form the textile layer 1 of the mat. Anedging strip 44 is located adjacent each edge of the backing layer 22,between the backing layer and the fabric layer 34. The fabric layeroverlaps the edging strip 44 by about 1-2 cm. The edging strip 44 may bemade for example of unvulcanised rubber, and may have a thickness oftypically 0.35-0.45 mm and a width of 2-5 cm.

FIG. 7 is an enlarged cross-sectional side elevation of the modifiedmat, showing an edge portion of the mat after completion of the pressingoperation. The rubber crumb/binder mixture has been consolidated to forma backing layer 2 and the fabric layer has been bonded to the backinglayer to form the textile layer 1 of the mat. The edging strip 44 isbonded to the upper face of the rubber crumb backing layer 2 and ispartially overlapped by and bonded to the textile layer 1.

The edging strip 44 hides the rubber crumb backing layer 2 so that theborder portion of the mat has the appearance of a conventional rubberbacked mat with a solid rubber backing. This may be desirable in certaincircumstances for aesthetic reasons. It also prevents dust and dirt fromcollecting in the small voids between the crumbs in the upper face ofthe rubber border to provide a cleaner appearance. In addition, theedging strip increases the tear strength of the mat border. This in turnallows a larger crumb size to be used, which reduces costs and providesincreased stability on carpeted surfaces.

Edging strips 44 may be provided on just the two longitudinal side edgesof the mat (particularly in the case of continuous matting), or on allfour edges of the mat. The strips 44 may be bonded to the backing layer2 and the textile layer 1 by vulcanisation during pressing, or by usinga glue or a thermoplastic adhesive. The strips 44 may be made of othermaterials, including for example thermoplastic materials. The strips mayalso be pre-applied to the fabric layer, prior to pressing, either byglue or vulcanisation. After pressing, any portion of the backing layerthat extends beyond the edging strip and, if necessary, the outer edgeof the edging strip 44 may be trimmed off to provide a flush edge.

Other mats can also be made according to the invention including, forexample, floor mats such as poster mats or foam sandwich mats, tablemats, drinks mats and bar runners.

1. A method of making a floor mat with a tufted pile textile surface andan elastomer backing, the method comprising the steps of (a) mixingelastomer crumbs and a binder, (b) depositing the crumb/binder mixtureto form a crumb/binder layer, (c) placing a textile surface elementcomprising tufts of yarn tufted into a tufting substrate on thecrumb/binder layer to form a mat assembly, (d) pressing the mat assemblyin a heated press, the heated press having an inflatable diaphragm and asingle heated platen having a plurality of zones, a first zone being alow temperature zone and a second zone being a higher temperature zone,said pressing step being used to set the binder, thereby consolidatingthe elastomer crumbs comprising the crumb/binder layer to form anelastomer backing that includes voids between the elastomer crumbs, andbonding the textile surface element to the elastomer backing, whereinthe mat assembly is pressed at a pressure in the range 2-8 psig (14-55kPa) and is heated at a maximum temperature of 200° C. or less to forman elastomer backing with a density in the range 0.5 to 0.9 g/cm³,wherein the elastomer backing thickness has a deformability of about14-25% when the thickness is measured after application of 60 g weightand a 800 g weight are applied to the backing with a 10 mm diameterfoot, wherein the mat assembly is pressed in a plurality of stages,wherein the thickness of the elastomer backing comprising the matassembly is within the range of 60 to 100% of the thickness of theunpressed crumb/binder layer, wherein the mat assembly is transportedthrough the press on a conveyor, and wherein the crumb/binder mixture isdeposited on the conveyor using a spreader device that moves at aconstant speed relative to the conveyor.
 2. A method according to claim1, wherein the thickness of the elastomer backing comprising the matassembly is within the range of 65 to 85% of the thickness of theunpressed crumb/binder layer.
 3. A method according to claim 1 whereinthe mat assembly is pressed at a maximum temperature in the range 110°C. to 140° C.
 4. A method according to claim 1 wherein the mat assemblyis pressed at a maximum temperature of about 125° C.
 5. A methodaccording to claim 1 wherein the binder is selected from the groupcomprising thermosetting and water curable polymeric materials andmixtures thereof, and the mat assembly is pressed in a plurality ofstages including at least one low temperature stage followed by at leastone higher temperature stage.
 6. A method according to claim 1 whereinthe binder is selected from the group comprising Thermoplastic polymericmaterials, hot melt binders and mixtures thereof, and the mat assemblyis pressed in a plurality of stages including at least one hightemperature stage followed by at least one lower temperature stage.
 7. Amethod according to claim 1 wherein the mat assembly is transportedthrough the press in a plurality of steps, so that it is pressedsequentially in each of the plurality of zones.
 8. A method according toclaim 1 wherein the spreader device includes a vibrating doctor blade.9. A method according to claim 1 wherein the textile surface elementplaced on the crumb/binder layer is a continuous textile surfaceelement.
 10. A method according to claim 1 wherein separate textilesurface elements are laid consecutively on the crumb/binder layer.
 11. Amethod according to claim 1 wherein mat borders are produced byspreading the crumb/binder mixture over a larger area than the textileelement or elements.
 12. A method according to claim 1 wherein theelastomer crumb is crumbed vulcanized rubber.
 13. A method according toclaim 1 wherein that the elastomer backing has a bulk density in therange 45 to 70% of the solid density of the elastomer crumb material.14. A method according to claim 1 wherein the elastomer crumb is crumbedvulcanized nitrile rubber and the elastomer backing has a bulk densityin the range 45 to 70% of the solid density of the elastomer crumbmaterial.
 15. A method according to claim 14 wherein the elastomerbacking has a density in the range of from 0.7 g/cm³ to 0.9 g/cm³.
 16. Amethod according to claim 14 wherein the elastomer backing has a bulkdensity in the range 55 to 70% of the solid density of the elastomercrumb material.
 17. A method according to claim 16 wherein theCrumb/binder mixture includes at least 10% by weight powdered elastomercrumb and from 9 to 20% binder.
 18. A method according to claim 14wherein the crumb size is substantially in the range of 2 to 4 mm.
 19. Amethod according to claim 1 wherein the elastomer backing has athickness of at least 1 mm.
 20. A method according to claim 1 whereinthe crumb/binder mixture includes at least 10% by weight powderedelastomer crumb.
 21. A method according to claim 1 wherein thecrumb/binder mixture includes less than 1% by weight powdered elastomercrumb and from 2 to 12% of binder.
 22. A method according to claim 1wherein the crumb/binder mixture includes from 2 to 20% by weight ofbinder.
 23. A method according to claim 1 wherein the binder is apolyurethane MDI binder.
 24. A method according to claim 23 in which thebinder is selected from the group consisting of (i) a 4,4-methylenedi-p-phenylene isocyanate (MDI) polyurethane one-component adhesive and(ii) a 4,4-methylene di-p-phenylene isocyanate (MDI) polyurethanetwo-component adhesive.
 25. A method according to claim 23 in which thebinder is a solvent-free one component polyurethane adhesive.
 26. Amethod according to claim 1 wherein the binder is a hot melt binder. 27.A method according to claim 1 wherein the crumb/binder mixture includespowdered additives selected from the group consisting of anti microbialadditives, anti-flammability additives, pigments, and anti-staticadditives.
 28. A method according to claim 1 wherein an edging strip isbonded to the elastomer backing adjacent at least one edge thereof. 29.A method according to claim 28 wherein the textile surface elementpartially overlaps and is bonded to the edging strip.